Improvement in wagon-jacks



M. D. WILLIAMS -& W. H. DODGE.

Wagon-Jack. I

No. 208,940. Patented Oct. 15,1878.

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' Ma 1 0 M 0M4 UNITED STATES PATENT OFFICE.

MILES D. W'ILLIAMS AND WALLACE H. DODGE, OF MISHAYVAKA, IND.

IMPROVEMENT lN WAGON-JACKSQ Specification forming part of Letters Patent No. 208,94 0, dated October 15, 1878; application filed April 3, 1878.

To all whom it may concern Be it known that we, MILES D. VILLIAMS and WALLACE H. DODGE, of Mishawaka, in the county of St. Joseph and State of Indiana, haveinvented a new and useful Improve ment in WVagon-Jacks and that the followin g is a full and exact description of the same, reference being had to the accompanying drawing, wherein- Figure 1 is a perspective view of our jack. Fig. 2 is a sectional elevation of the same. Fig. 3 is a plan of our jack.

The object is to construct a jack of cheap material and in a manner which will give efficiency with such simplicity of structure as will enable any ordinary mechanic to construct it of material commonly found about every carpenter-shop.

This invention belongs to that class known as lever-j acks, wherein there is a standard or fulcrum resting on the ground, a lifting-slide, and a lever to produce motion between the above-named parts.

These general features being old, we make no claim except to their particular structure and organization, as described herein, and shown in the accompanying drawings.

A is a single standard, set at its base in a foot-piece, B. The front side of the standard A is provided with a central longitudinal groove, I), adapted to receive and guide the slide 0, which is provided with a correspondin g rib, f, along one edge. This rib or feather and its groove give the parts a very strong union without impairing the freedom of their movements up and down, and render it unnecessary to provide guides or fastenings other than a stay-bolt, J, which passes through said rib and slideO and through a slot, 1 made in the standard A for that purpose. The bolt J has a broad head to cover the slot at and slide upon the solid wood on either side. This structure is exceedingly simple and cheap to construct, and efficacious. The rib and groove form a complete guide for the slide, bear all the lateral strains incident to use, and the bolt J serves to keep said slide up in position. The strain upon the bolt J is always a simple tensile strain without any side deflection or shear.

A cam, D, is pivoted by the bolt 9 in a slot, h, near the base of the standard A, and the lower end of the slide (J, which is rounded for the purpose, rests upon the cam-surface of D. Different positions of the cam D and its lever d are shown in full and dotted lines in Fig. 2, and the corresponding variations in the position of the slide 0 are likewise shown. The operation of the cam D is well understood, and requires no elaboration here. As the lower end of the slide 0 necessarily rests upon the cam-surface of D, and goes up or down as the said cam is rotated, the weight of the slide 0 always rests upon a point at one side of a line vertical to the axis of the pivot g, and therefore, if the cam-surface is continuously recedin g from the pivotal center, there will always be a tendency under stress to fly back-15. 0., to cause the cam to recede and permit the slide to descend. Such tendency we counteract by changing the direction of the cam-surface at or about the point q, preferably from said point. We make said surface K straight fora distance as a chord, so that the slide will descend slightly as it passes upon said straight part, and thereby securely hold the lever din position.

We are aware that others have effected a lock of the lever by the downward pressure of the superimposed mass; but we are not aware that this effect has hitherto been produced with a single pivoted lever and changed direction of the cam-surface.

Having described our invention, what we claim as new is-- A wagon-jack having a post, A, provided with a foot-piece, B, and slots h i, and groove b, combined with the slide 0, provided with the rib f, adapted to the groove 1), sliding tiebolt J, and the cam D, pivoted in the slot 71, and provided with the locking-surface k.

MILES D. WILLIAMS.

XVALIJAGE H. DODGE. Witnesses CHARLES H. WooDBURY, HARLOW' DODGE- 

